The BU90054GWZ are a high efficiency 6MHz synchronous step-down switching regulator with ultra low current PFM mode. It provides up to 1.0A load current and an input voltage range from 3.0V to 5.5V, optimized for battery powered portable applications. BU90054GWZ has a mode control pin that allows the user to select Forced PWM(Pulse Width Modulation) mode or PFM(Pulse Frequency Modulation) and PWM auto change mode utilized power save operation at light load current.